By Sarah Abel, Jeffrey A. Lindley, P.E., and Jeffrey F. Paniati, P.E. This is an excerpt from the article originally appeared in the May issue of ITE Journal. Institute of Transportation Engineers, All Rights Reserved.
As an active Road to Zero member, the Institute of Transportation Engineers is currently guiding the national effort to prioritize safety through a creating a safety culture and advancing a Safe System approach, one of the three main recommendations from The Road to Zero: Achieving Zero Deaths by 2050 report. More than two dozen leading national transportation and safety organizations and technical experts, including the Federal Highway Administration and the National Highway Traffic Safety Administration, are participating in this effort.
In moving from vision to implementation, we are working on increasing the understanding and application of Safe Systems and Safety Culture concepts and practices, identifying key tools and references, creating case studies from leading jurisdictions, and finding ways to integrate knowledge into practice.
Safe System Approach
A Safe System approach can help us get to zero fatalities by creating a "safety net" that uses mutually reinforcing approaches to create safer roads, safer speeds, safer vehicles, safer users and effective post-crash care. Sweden was the first country to enact a Vision Zero policy using a Safe System approach in 1997, marking a fundamental shift to a shared responsibility and system-based approach to improving safety, with increased attention on the design and designers of the roadway to prevent crashes and limit their severity. The Prioritizing Safety Steering Committee explored and applied below concepts that underpin a successful Safe System approach:
- Humans make mistakes that can lead to road crashes
- The likelihood of severe injury increases dramatically with increases in speed
- It is a shared responsibility to ensure road crashes do not lead to serious or fatal injuries
- All parts of the system must be strengthened so that if one part fails, road users are still protected
- A proactive approach should be taken rather than waiting for events to occur and reacting
- No death or serious injury should be accepted in return for faster mobility
- It is critical to identify and understand crash causation and make evidence-based decisions
A Safe System Explanation and Safe System Framework were created to help support a shift in the way transportation professionals think about road-related crashes, injuries and fatalities. The framework is built around the goals of reducing human error and accommodating human injury tolerance.
Reducing Human Error
Separating users in space. Creating separate spaces for different users creates physical separation enhancing safety, such as separated bike lanes, pedestrian refuge islands or clear zones.
Separating users in time. Separating users in time allows different users to use the same space at different times, such as a pedestrian scramble phase.
Increasing Attentiveness and Awareness. Alert users to potential hazards and/or the presence of other users, including increasing visibility, attentiveness and reducing impairment.
Accommodating Human Injury Tolerance
Reduce Speeds. The laws of physics dictate that greater harm will occur at high speed, and the greater the mass of a vehicle the more harm it will inflict on others. Reducing speed in the presence of vulnerable road users is a key Safe System strategy. In urban areas, this strategy starts with reassessing speed limits and moving toward the use of context-specific target speeds in lieu of the 85th percentile speed for speed limit setting. The use of traditional or automated enforcement is also a key tool to support lower speeds.
Reduce Impact Forces. Traditionally, this is accomplished by protecting the user inside a vehicle by improving the crashworthiness, use of restraint systems and air bags. Similarly, road infrastructure is being designed to reduce impact forces, such as the use of guardrails, crash cushions, roundabouts and turn hardening.
This framework represents a starting point to aid practitioners in the implementation of design and operational treatments that will save lives and reduce serious injuries through a Safe System approach.
Next Steps
The Prioritizing Safety Steering Committee is developing a Prioritizing Safety roadmap and action plan, with more information available later this year. To view available resources and learn how to apply the Safe System approach, visit the ITE Safe System Technical Resource page. View the full version of this article as it appeared in the May 2020 ITE Journal.
